Snap switch



Jan. 1, 1957 A. A. ALLEN 2,776,347

SNAP SWITCH Filed June 16, 1955 j g4 INVENTOR.

ALAN/4. AME/v @j www United States Patent O SNAP SWITCH Alan A. Allen,Beverly Hills, Calif.

Application June 16, 1955, Serial No. 515,876 s claims. (ci. zoo- 67)This invention relates to a snap switch construction which uses a switchblade of resilient material and which isvpre-stressed in a manner to setup a deformation, creating one area of high sensitivity that, whensubject to relatively small movement, will impart to another area of`the blade a rapid and relatively larger movement or displacement. ln aminiature snap switch of the above character, the blade may be in thenature of one-half inchlong and be made of flat spring stock some .002"to .004l thick. Although such blades may be initially placed understress so as to have snap action, their action is not always uniformand, therefore, not wholly dependable. Blade chatter is frequent duringaction of the switch, as well as blade vibration. Also, the blademovement may be subject to high momentum forces which may materiallyaiect the action thereof. w

Accordingly, it is an object of the invention to provide, in a switch ofthe character referred to and having a stressedj switch blade, means toeliminate chatter and vibration of the blade and, thereby, provide forgreater uniformity of the blade movement and improved control of saidmovement.

Another object of this invention is to provide a switch blade that isadapted to be transversely flexed to induce longitudinal lieXure and toso conne, restrict and/or control the action of said blade in thevicinity of such transverse ilexure as to largely eliminate bladechatter and vibration.

A further object of the invention is to impart a strong return force tothe switch blade whereby positive return, after actuation, is assuredunder all conditions of operation, under both static and high momentumconditions.

As the following detailed description of the invention proceeds, theforegoing objects and other objects, features and advantages of theinvention will become more clearly evident. Said description is based onthe accompanying drawing of a preferred form of the invention and inwhich like numerals designate similar parts throughout the severalviews.

In the drawing:

Fig. 1 is a partial side elevational and partial longitudinal sectionalview of a snap switch embodying the features of the present invention.

Fig. 2 is a plan view thereof with a portion removed to expose theinterior construction.

Fig. 3 is a perspective view of a novel element that cooperates with theblade of said switch to control the action of the latter.

Fig. 4 is an enlarged fragmentary sectional view as taken on line 4 4 ofFig. l, the switch blade being shown in unactuated condition.

Fig. 5 is a similar view showing the actuated condition of the blade.

Referring to the drawing in greater detail, the switch comprises atwo-part dielectric housing 5 formed as a base or body 6 and a cap orcover '7. Said base is provided with a platform 8, at one end, and witha support portion 9, at the opposite end.

Patented Jan. l, 1957 Platform 3 supports a switch blade 10 while theportion 9 carries a contact plate 11. Beneath plate 11, the housing baseor body 6 mounts a second contact plate 12. A contact 13 on the free endof switch blade 10 normally is in electrical contact with plate 11, asshown, and may be moved into electrical contact with plate 12 when theblade is downwardly flexed.

The switch blade 10 is secured to platform 8 by the end 14 of a terminal1S. Terminals 16 and 17, respectively, secure the contact plates 11 and12 in place.

The housing cover or cap 7 is formed to have a socket 18 in whichoperates an actuator 19 for the spring base 10. Said actuator isprovided with transversely spaced projections 20 that are spaced fartherapart than the width of platform S (see Fig. 2) and are adapted to pressagainst opposed lateral portions of the spring blade so as to ilex thesame across the platformv 8.

Since the contact 13 holds the spring arms 21 of the blade 10 flexedtoward each other, as shown in Fig. 2, said blade is stressed and hasvanupwardly eXcd normal position to bring the contact 13 into engagementwith the under face of contact plate 11 as in Fig. l. When the actuator19 is pressed, the resulting transverse ilexure of the blade across theplatform 8 (Fig. 5) causes reverse longitudinal flexure of the blade tomove the contact 13 into engagement with the upper face of contact plate12. Also, since, heretofore, the blade was aflixed to its support at theeXtreme end remote from contact 13, the switch blade was prone tovibrate under certain conditions, as for instance shock. When shock isgreat enough, the blade may flutter and cause loss of electrical contactor even shift from one Contact to the other. Also, when actuated, theblade was subject to chatter to deleteriously affect the operation.`Further, dependence on uniform action could no-t be had under differentconditions of use, ashereinbefore mentioned.

To obviate the above faults, the present switch structure provides acontrol eiement 22 that retains or restrains the spring blade so thatthe same may function uniformly. As shown, said element 22 is held inplace by the reduced end 23 of terminal 15 and a head 2.4 on said endtightly afxes the same in position to overstand the portion of theswitch blade that rests upon platform As can be seen from Figs. 4 and 5,the top of platform 8 is found to be transversely convex so as toprovide said platform with longitudinal transversely spaced lands 3althat serve as supports for the blade part 21a between the head 24 andthe bifurcation formed by the spring arms 21. Due to the mentionedupward flexure of blade arms 21, the blade part has a slight transverseflexure that is concave, as seen from above. lt is when this transverseflexure is reversed that the switch blade snaps into contact with plate12.

Control element 22 has an elongated end 25 that eX- tends from atransverse bend 26 at an obtuse angle 27 with respect to lthe part 2Sthat is caught under the head 24. Said end 25 may be tapered to providea point 29. It will be clear, therefore, since part 2S seeks a atposition against the blade, the point 29 of angularly bent part 25impinges on the blade part 21a between the lands 8a, as can be seen inFig. 4. This tends to increase the transverse flexure of the blade and,thereby, materially reduce blade Hutter or chatter. The part of theblade engaged with table 30 remains substantially flat while the part21at engaged with lands 8a assumes the exure indicated.

Also, since the impingernent of point 29 rmly holds the blade partagainst the platform lands Se, the free length of the blade is reduced.The same effects a further reduction or elimination of vibration andchatter.

When actuator 19 is depressed, as shown in Fig. 5, to reverse thetransverse exure of blade part 21a and snap the button 13 to engageplate 12, the point 29 of element 22, being substantially immovable,prevents flexure of the middle portion of the blade part 21a. Thus, onlythe lateral edge portions 31 of part 21 can iiex.

Because of this resistance to transverse fleXure of the blade partbetween lands Se, a positive force is induced that is effective on saidedge portions 31 to return them quickly to the condition of Fig. 4 uponrelease of actuator 19.

Since variations may be made in the present means that would fall withinthe scope of the invention, I Wish to reserve to myself all suchvariations and modifications that fall within the spirit and scope ofthe appended claims.

I claim:

l. In a snap switch provided with a switch blade having one end affixedto and supported on a platform and having a longitudinally flexible freeend, said switch having an actuator to transversely flex a portion ofthe blade supported by said platform, the improvement that comprises amember in rm impingement with the blade between the points of transverseflexure, said member having a portion affixed with the blade to theplatform and a bent portion having a corner edge in the mentionedimpingement with the blade.

2. In a snap switch provided with a switch blade having one end aliixedto and supported on a platform and having a longitudinally flexible freeend, said switch having an actuator to transversely flex a portion ofthe blade supported by said platform, the improvement that comprises amember in firm impingement with the blade between the points oftransverse flexure, said platform being provided with longitudinal andtransversely spaced lands, and the mentioned member impinging the bladeon the portion between the lands.

3. In a snap switch provided with a switch blade having one end affixedto and supported on a platform and having a longitudinally flexible freeend, said switch hav- Ving an actuator to transversely flex a portion ofthe blade supported by said platform, the improvement that comprises amember in firm impingement with the blade between the points oftransverse flexure, said platform being provided with longitudinal andtransversely spaced lands, and the mentioned member being provided witha pointed end bent to impinge on the portion 0f the blade between thelands.

4. In combination, a platform, a pre-stressed switch blade having oneend supported by said platform and having an opposite free end, actuatormeans to transversely flex the blade across the platform and, thereby,longitudinally Hex the free end thereof, and a iiexurecontrollingelement fastened to the platform-supported portion of the blade and inimpingement with the blade at the point of transverse iiexure.

5. The combination according to claim 2: the exurecontrolling elementbeing bent to form an obtuse included angle between its ends, and meansto stress said element to flatten said angle and provide corner-edgeimpingement of said element with said blade.

6. In combination, a platform provided with a pair of longitudinal andtransversely spaced lands, a prestressed switch blade having one endengaged with the lands of said platform and having an opposite free end,actuator means to engage said land-engaged portion of the bladeoutwardly of the lands to transversely fiex said one end of the bladeand, thereby, longitudinally tiex the free end thereof, and aflexure-controlling element fastened to the platform-supported portionof the blade and provided with an end in firm impingement with thelatter blade portion between the lands.

References Cited in the file of this patent UNITED STATES PATENTS2,024,362 Hoopes Dec. 17, 1935 2,275,642 Nordberg Mar. 10, 19422,649,520 Hartz Aug. 18, 1953

